These old Dodge trucks do grow on you.

A great soft cover book that provides a lot of information about Dodge trucks:
Dodge Pickups
history and Restoration Guide
1918 - 1971
By Don Bunn and Tom Broenell
The book provides a break down of Dodge trucks by "eras" between the introduction of Dodge trucks in 1918 up to the end of the 1971 model year. An "era" of a Dodge truck is the time period between one major redesign and the next major redesign. Each era provides a history of the truck industry and the reasons of the need for the new design. It breaks down the list of standard equipment, and the list of optional parts. It lists major mechanical advancements and body modifications year by year in each era. There were a huge list eras and of changes the Dodge truck line went through between 1939 and 1958. It even provides how much of the truck market share the Dodge trucks had through the process, and things that may have effected those changes.

I'm sure the book is no longer in print, but maybe you can buy a used copy. I know I have wore out the binding on my book searching for information. I'm also sure there are some inaccuracies (as there are in most books of this kind), but there is a wealth of info in the book.

As a side note. Those 49-54 Dodge trucks had a huge front end that did a better job blocking the wind then it did splitting it up to go around the truck. Trucks of that era were primarily work trucks, and most of them were used to haul something from point A to point B, and the speed was generally 45-50 mph. At those speeds, the wind resistance was not an issue, but driving one of these trucks at 60 mph, that poor wind resistance becomes a factor. If you are driving into a head wind, that flathead 6 might not be able to reach 60 mph (brutal facts), If the truck is carrying a max load and driving into a head wind, it might not be able to reach 50 mph! Pull a hill loaded up? Maybe 40-45, but the wind is no longer much of a factor. There were reasons a V8 was an added option by May of the 1954 model year. The V8 could push that loaded poor aero body through the head wind at higher speeds then the 65 mph speed limit. You knew when the loaded truck hit the hill, but you didn't loose 1/2 your speed.

The flathead 6 was a great motor. Chrysler used them for many years, then the flathead went into industrial use, but starting in the mid 30s the HP and cubic inch increased regularly and by the end of the flathead 6 truck age, a 265 CI 110 HP version was available. The available V8s during that time frame were rated at nearly 2x the 265 HP rating. The way HP was rated changed in the early 60s, changed from a max HP (off the flywheel) to a net HP (through the drive train). Comparing the old HP numbers to the new HP numbers is inaccurate. Most flathead 6 motors were rated at max HP while most modern V8s are rated at net HP.